The present invention is generally directed to devices useful in prospecting for valuable metals or minerals and, more specifically, to devices for sampling placer deposits to determine the presence of such valuable metals or minerals.
Placer deposits of various metals or minerals such as gold are fairly widespread in occurrence throughout portions of the world. These deposits generally comprise sand, gravel and other alluvium and eluvium containing concentrations of metals or minerals of economic importance and are the result of natural mechanical concentration wherein the heavy, chemically resistant and tough minerals are separated by gravity from the light and friable materials. The most economically important placer deposits generally are those formed by the action of streams where the flow of water creates placer deposits on the inside of meander bends of the stream.
In prospecting for the economically valuable concentrations of minerals or metals within a placer deposit, it has been the general practice to sample the deposit at various spaced locations in a uniform grid pattern by one or more methods such as shaft sinking, caisson sinking, churn drilling, open cuts and the like. However, for the amateur or weekend prospector who has limited time, manpower and equipment, these methods for sampling placer deposits are not generally feasible in terms of time and effort. Therefore the need exists for a small yet rugged device for sampling placer deposits which can normally be operated by one person and which can provide accurate and valuable information as to the composition of a particular portion of a deposit.
Devices for obtaining samples of earth are known in the art. For example, U.S. Pat. No. 507,018 to Lacy, U.S. Pat. No. 1,862,339 to Highmark, U.S. Pat. No. 2,454,952 to Starkey, and U.S. Pat. No. 3,036,638 to Parsons disclose such devices. In addition, probe-like devices for obtaining samples of flowable particulate solids such as grain are known from U.S. Pat. Nos. 230,121 to Frost and 1,087,847 to Graunfels, among others. However, none of the above-mentioned patents teach a device having the necessary structure and operation so as to be adapted for use in simultaneously obtaining a plurality of samples from mineral deposits such as placer deposits in a simple and efficient manner.